The present invention pertains to a rotary compressor for respiration systems. Such respiration systems are used mainly in the area of medicine, where closed respiration systems with rebreathing are used for various reasons.
A known field of application in the area of medicine is, in particular, the area of anesthesia, where the circulation of the expired gases and of the newly added gases, e.g., oxygen, is desirable, e.g., in the case of narcotic anesthetics. A rotary compressor for respiration systems, which is particularly suitable because of its properties for rapidly following the spontaneous breathing of the respirated patient, has become known from U.S. Ser. No. 08/965,256. However, such rotary compressors have not yet been able to be sterilized and are therefore unsuitable for use as a gas delivery means in respiration systems with rebreathing in a closed circuit. Furthermore, the separation between the electric components and the breathing gas with increased oxygen concentration is not yet sufficient, so that the oxygen additionally added can be added only in the open respiration system and only behind the rotary compressor and it must therefore be metered dynamically.
The primary object of the present invention is to propose an improved rotary compressor for respiration systems, which can be washed and sterilized, on the one hand, and makes possible a reliable separation of the breathing gas from the electric components, on the other hand.
According to the invention, a rotary compressor for respiration systems is provided with an electrically driven compressor wheel, which is mounted by means of an aerodynamic gas slide bearing.
The gas slide bearing includes axially and radially loaded surfaces. The axially loaded surface of the said compressor wheel may have grooves. The axially loaded, nonmoving housing surface may have grooves. Axial opposite bearing surface of the said compressor wheel may also have grooves. The nonmoving housing surface of the axial thrust bearing may also have grooves. The radially loaded surface of the compressor wheel and/or the radially loaded surface of the thrust bearing of the compressor wheel may have grooves. These grooves may be designed in the form of logarithmic spirals.
The rotation of the compressor wheel may be brought about by the cooperation of a permanent magnet physically connected to the compressor wheel adjacent to the axis of rotation with a magnetic field, which rotates around the axis of rotation and is generated by coils in the radial thrust bearing.
The compressed gas is preferably fed in, in parallel to the said axis of rotation of the said compressor wheel. The compressed gas leaves the compressor wheel at right angles to the axis of rotation.
The compressor may be a radial compressor or side channel compressor.
A method is also provided with a drive for breathing gases transported in closed circuit in a respiration system.
One essential advantage of the present invention arises from the use of the breathing gas itself as a lubricant between the sliding surfaces moving in relation to one another, so that the slide bearing is completely maintenance-free. Due to the design of the aerodynamic gas slide bearing, the rotor and the stator are separated from one another in a completely wear-free manner, and the generation of noise is additionally particularly low compared with prior-art rotary compressors, which is caused by a corresponding stress on the usual rolling bearings because of the relatively high speed of rotation.
In addition, the simple design of the rotary compressor according to the present invention makes it possible to remove, clean, sterilize and reinstall the components through which breathing gases flow during field use, so that use in a respiration system with breathing gases transported in a closed circuit becomes possible in a safe, hygienic and convenient manner.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.